While most of us were sleeping, a dedicated team was constructing Auckland’s newest water storage reservoir. Although there are some more late nights planned on the project, overnight (25-26 October) the team completed the fifth night-time roof pour for the third reservoir at the Redoubt Road Reservoir complex
The construction of the in-situ concrete elements of the roof are completed at night to guarantee a robust supply of concrete when there is little traffic and temperatures are cooler.
The complex currently stores up to 120 million litres, and more than 80 per cent of Auckland's treated water passes through it every day.
The $60 million reservoir will caters for Auckland’s future growth and will provide improved resilience with an additional 45 million litres of storage – the equivalent of 18 Olympic-sized swimming pools.
Project manager Martin Hughes says with the roof now 99% complete, the reservoir is on track to be commissioned and brought into service early in the new year.
“So far, the team has poured more than 800 cubic metres of concrete to create a 100mm-thick reinforced concrete layer. This layer ties the precast elements of the roof together and to the top of the walls. The pitch of the roof is flat to allow rainwater to drain into the external drainage system.
“The concrete roof also has a waterproofing membrane applied to it to ensure that there is no chance of the treated water stored in the reservoir becoming contaminated.”
Hughes says the last pour for the roof will take place next month and will be the smallest of all six roof and four floor pours – completing the reservoir structure.
“However, all the equipment being used inside the reservoir will be lifted out before the final roof pour.
“After that, our attention will turn to finishing the installation and testing of the reservoir’s pipe transmission network, followed by water tightness testing of the reservoir.
“The water tightness test will determine if the reservoir is leaking by checking its wall and floor joints for visible leaks over the course of a week.
“We do this by filling the reservoir over four to five days until it reaches its maximum operating level - approximately six metres deep.
“Once it reaches this level, the project team will visually monitor the reservoir for leaks and measure the level of the water in the reservoir daily.”
Hughes says the effort the project and construction teams have put into building the reservoir – day and night – has been immense.
“I'm so impressed with the efforts of everyone who has worked on the project – especially when resolving technical issues or having to deal with the various challenges we have encountered during the construction process, like the extreme weather events earlier in the year.
"I'd also like to thank the residents who live close to the site for their understanding and patience as we work to deliver this critical infrastructure that will improve the resilience of our water network for all Aucklanders.”
Board member John Spiller says adding another reservoir will help future-proof supply.
“The project has involved building and connecting a new reservoir, first by establishing an access road, and now building the reservoir itself – work that is nearing completion.
“Having seen what is involved, the complexity of the operation, and just the huge amount of work that is needed, I don’t think I’ll ever turn on the tap and take water for granted again.”